Was the content of the letter Mei Changsu wrote to Ni Huang at the end of the Langya Board mentioned in the novel?

At the end of the Langya Board, Mei Changsu's letter to Ni Huang was mentioned in the novel. This letter was written by Mei Changsu to Ni Huang after he knew that he was about to pass away. It expressed his gratitude to her and his longing for her, and also revealed the secret that had always existed between them. In the letter, Mei Changsu told her that he had always thought Ni Huang was a smart, brave and intelligent person. He thanked Ni Huang for her support and trust and expressed that he would always miss the time with her. The content of this letter was very touching in the novel, allowing the readers to feel the deep feelings between Mei Changsu and Ni Huang.